166 BACTERIA IN DAILY LIFE 



and obtained very similar results. With regard 

 to both these varieties of pathogenic bacteria, he 

 mentions that their action upon animals was not 

 quite so rapid as is characteristic of normal speci- 

 mens of these micro-organisms, thus confirming 

 the experiments in this direction made with frozen 

 tubercle bacilli. 



Not content with the exhibition of their powers 

 of endurance, Dr. Belli determined to make yet 

 another demand upon the vitality of these bacilli. 

 For this purpose he immersed them in the liquid 

 air itself, thus bringing them into direct contact 

 with it, effecting this by lowering into the liquid 

 strips of filter-paper soaked in broth containing these 

 bacilli. But, in spite of remaining for the space 

 of eight hours in these surroundings, they emerged 

 triumphant, exhibiting no modification whatever 

 either in their structure or pathogenic properties. 



There are doubtless many other trials yet await- 

 ing bacteria, to which they will most certainly be 

 submitted before the limits of their powers of 

 endurance have been adequately tested, but it is 

 difficult to conceive of a severer strain upon their 

 vital resources than the imposition of the con- 

 ditions of which the above is but a brief sketch. 



The triumphs achieved in this direction by 

 micro-organisms are, however, closely approximated 

 by the remarkable record established, according to 



